Answers

The jinn are among the creatures that Allah (swt) created. The jinn race was created from fire.

"And the Jinn race, We had created before, from the fire of a scorching wind." (Quran 15:27)

They have intellect, freedom and power to choose between right and wrong. These characteristics suit the need for them to worship God.

"I have only created Jinns and men, that they may serve Me." (Quran 51:56)

They are being hold responsible for all their actions like humans do in the Judgement Day.

"On that Day no question will be asked of man or Jinn as to his sin." (Quran 55:39)

The jinn with sins are going to be placed in Hell.

He will say: "Enter ye in the company of the peoples who passed away before you - men and jinns, - into the Fire." (Quran 7:38)

Satan on the other hand is the enemy to mankind.

"Said (the father): "My (dear) little son! relate not thy vision to thy brothers, lest they concoct a plot against thee: for Satan is to man an avowed enemy!" (Quran 12:5)

Satan are consisted of both men and jinns.

"Likewise did We make for every Messenger an enemy,- evil ones among men and jinns, inspiring each other with flowery discourses by way of deception. If thy Lord had so planned, they would not have done it: so leave them and their inventions alone." (Quran 6:112)

Yes, both can posses people.

"Those who devour usury will not stand except as stand one whom the Evil one by his touch Hath driven to madness..."

(Quran 2:275)

Iblis is a jinn and satan both at the same time.

"But Satan whispered evil to him: he said, "O Adam! shall I lead thee to the Tree of Eternity and to a kingdom that never decays?"

(Quran 20:120)

""Bow down to Adam": They bowed down except Iblis. He was one of the Jinns..."

Well Shaytaan is of the Jinn. Jinn are creations of God who, like humans, have free will. They were created before humans out of smokeless fire. There are good Jinns and Bad jinns. The bad ones usually follow shaytaan. There are references in the Hadith saying that there is three types of jinn, one that fly's, another which lives in houses and the third that takes the form of dogs and snakes (if I am not mistaken) there is a surah in the Quran called al-jinn. Read it. It talks about how the jin converted. The jinns have different powers from men and nobody knows their true form. The evil Jin are used by magicians for evil chores. It is debated whether or not a jinn can possess humans. There have been some accounts and the best remedy to magic and/or being troubled by the jinn is the Quran. Hope that cleared things up a little. About taking human form, I'm not sure. There's a hadith that says if you find a snake in your house and after beating it or something it comes back, kill it because it may be a jinn. And the jinn can help so called psychics whether they are aware or not because there is a place where the angels talk about the future and they eavesdrop and come back to tell the person things. That's why some fortunes come true but with a truth they spread many lies. And when they are caught Allah strikes them as the run away and that's why you see shooting stars. However this practice seems to have briefly come to a halt when the prophet Mohammad was being revealed the ayahs of the Quran. I think this is also in the chapter al jinn

Both are jinns there are good and there are bad jinns. Shaitan is the father of all Jinns. They are shape-shifters and can transformed into anything, human, animal, tree, rock, water, wind ETC. few can do many things but most jinns can do only a few things like some can fly, some can heal, some can affect weather and so on... know this a good jinn will never have any contact with you. like what do you want to know exactly? I don't want to rant on... what do you exactly want to know?!

The jinn can be good or bad, they have free-will like humans. The evil jinn are called the shaitan or devils. Satan himself was a jinn who became a devil/shaytan. Some mistake him as a "fallen angel", this error is understandable as angel simply meant messenger and people in Europe during the middle ages didn't understand alot of things. But the real angelic beings are made from light and cannot fall and become devils, only the jinn and humans fall from grace and committed sins.

okay now for the better answer ^^
Shaitan is a jinn. Jinn are made out of fire. Bad jinn can possess people. Shaitan is a name that we call iblis because he went against god's will. And also shaitan is a name given to all of shaitan's children.

Jinn literally means something invisible. Snakes are called Jaan in arabic. This is because they usually are hidden from the eye. Quran describes Jinn in various contexts. The word is applied to different entities, groups or persons according to the context.

http://www2.alislam.org/askislam/mp3/MEI_19850622_06.mp3

Shaitan, means the one who rebels, an adversary, a disobedient person. Iblees is called Shaitan because he rebelled. He is also desribed as being among the Jinns. Quran also uses this word in plural, shayateen.

Many people believe that Jinns are similar creatures like genies, demons, spirits etc, but Quran does not support this view. Jinns can be humans as well as animals. Tribes and nations who lived in the mountains, and remote places were called Jinns. Invisible creatures like bacteria and viruses are also called Jinn. People of rebellious nature are also called Jinn.

Shayateen are the opposite of angels. But they do not inhabit people and disturb them as popularly believed. Again, shayateen can be humans too, who cause hurdles in the way of truth and oppose the message of God.

Jinn are not bad. They are just creatures of Allah (SWT) like humans or animals. Jinn can not harm you, but there are other evil creatures that can possess you. Iblis is a jinn. Iblis is shaitan. Shaitan is who tries to misguide you. But the name of sahaitan is Iblis

Jiin and Shaytaan are both made from fire.
Shaytaan work for Iblis
Jiin are like us, theyre Kaffir and theyre Muslims, but if a Jiin is bad enough he/she is considered a Shaytaan

Both can posess people, but its hard for a Jiin and it uses a lot of their energy
Jiin can also shape shift but they cant do it completely so if they turned into a human there'd be something wrong.(horse feet or something ect:)